The present invention relates to manufacturing of composite members, and in particular to a method for manufacturing corrugated fiberglass members having improved strength and stiffness.
Fiberglass panels are commonly constructed by using short fiberglass fibers or filaments and a resin. The fibers consist of chopped strands less than about 2 inches in length which are randomly arranged in the panel. The panel is molded into the shape of a corrugated member in a continuous process. Such fiberglass designs are not intended to bear heavy loads since the transfer of loads through the chopped strands in the panel is haphazzard.
Another fiberglass construction technique uses a layer of continuous longitudinal unidirectional filaments and a layer of woven fiberglass filaments, known as woven roving, to lend strength to the article. See, for example, U.S. Pat. No. 4,029,172. This method produces stronger than conventional fiberglass panels but has some disadvantages in that the weaving of fiberglass filaments is expensive and results a high resin content in the panel produced.
There exists a need, therefore, for a fiberglass construction method which produces a panel which resists changes in shape when stressed and which maintains the stiffness and strength of the corrugation.
There exists a need for such a process which will develop corrugated fiberglass panels with greater strength and stiffness than that of conventional fiberglass panels utilizing random chopped strands or additional layers of woven fiberglass filaments.
There exists a need for such a method which can be operated as a continuous production process which produces a panel with optimum load bearing capability at a minimum of additional cost.